Improvement sn artificial teeth



ilNiTEn STATES PATENT OFFICE.

WILLIAM BALLARD, ou BROOKLYN, NEW. YORK.

IMPROVEMENT EN ARTIFlClAL TETH.

Specification forming part of Letters Patent No. 51,001. dated. November 21,1865.

To all 'whom-it may concern:

'Be it known that I, WILLIAM BALLARD, of Brooklyn, Kings county, State of New York, have invented certain "new and useful Improvements in 4Hard-Rubber or .Vulcanite fintended, but from an'experenceI derived at the expense of a large outlay of money and great sutferiu ganci privationsfor more than two years lastpast in tryin'g sets of artificial teeth made' by the most eminentdentists of the country, l became satisfied of the utter ii sufiiciency of such a device to retain the se of 'artificial teeth firmly in the mouth as el rule, though exceptional instances might be found, and indeed was so informed by one ofthe most` trustworthy dentists in the country, who had made three sets of teeth for me without affording; any satisfactory results, except that I must persevere to force nature .to .adapt itselt` to the artificial plate. Therefore, tooverv come thisunnatural method 4of adapting the artiiieiai set of teeth -to .the meuthis the impellingfcause that hasled me to this invention, the nature of which consists ini mak'- ing `a great number of air-chambers in the upper surface ofthe artificial plate,I extending from the ridge of. the gum quite up totand around the heartshaped airchamber, and thus' give'to the ridge of the gum an atmosphericpressure suction, as it may be called, as well as to the roei' ofthe mouth. By this means it will be obvious that the plate cannot tilt or bite down77 when masticating food on one side ofthe mouth, as would be the case When'the atmospheric traction "is confined to a single point at the middle of the'plate To describe my invention more particularly,

l will refer to the accompanying drawings. Iforming a part of the specification, the same letters of reference, wherever they'occur, referri-ng to like parts.4 l

Figure l is a perspective view of "au upper set of artificial teeth,'showiu`g thgauxiliary air-chambers. Fig. 2,is'a' lowerside-perspective view of a set of artificial teeth.

Letter a is a representation of a hard-rubber or `rulcanite plateffor anupper set of artificial teeth, and b represents theteeth secured to the same by any of ,the .usual and-well known. means for such purposes; In the' upper surface of theplate or that'surface which comes in contact with the roof of the moutl is formed 'a Alarge central air-chamber, c. As

this is the common and welllknown device for making atmospheric'- pressure sets of artili= cial `teeth I make no claim to it, tho gh do not consider a very large central air-chamber pro-v ductive ofK the'most vsatisfactory results, and thereforethe failure of so many dentists in trying to get atmospheric pressure, under the mistaken theory that the larger the single central air-chamber thegreater the tractidnofthe ence, therefore, has led me tomake--the c trai air-chambernot as large as dentists, com-A monly make it. But to 'obtain the requisite -'h'iount'of atmospheric-pressure traction I diffuse it over the surface of the plate bya series ot' auxiliary air-chambers, d,exte,ndiug from the gum-ridge up to Iand around the central air-chamber. vThese auxiliary air-chambers are notlessj than about au eighth of an inch in diameter, and having as much depth as the thickness of the plate'will permit.v

It will be obvious that the arenof these aux# iliaryair-'chanxbers is cf material consequence, because very small perforations would not act inther'oof of the-mouth to preserve atmos pheric traction, it being necessary to have a certain area, lessthan which the muscles ofthe mouth can `not ll the air-chambers.' It is this peculiarity that gives value tomy invention,

and .which has enabled meto sustaiua weigh-t* ot at l ast twenty-five pou'nds before the plate :could e displaced from my mouth, jwhen the three previous plates made by the same deutist, by the use of the single central air-ehamface thereof, from the gum-ridge up to and ber, failed to keep'their pla-ces on the least efsurrounding a central air-chamber, in the manfort to masticate food on either side of the jaw. ner and form substantially as hereinbefore set Having now described my invention, I will forth.

proceed to set forth what I claim and desire to WM. BALLARD, Y d secure by Letters Patentof the United States- Witnesses The new manufacture 'ofhard-rubber or "ul- R. S. ROWLEY, canite plates for sets ofl artificial teeth, hav- C. L. BARRITT. f ing auxiliary air-chambers in the upper sur- 

